CN111428889A - Device and method for dividing external field replaceable unit L RU - Google Patents

Abstract

The invention provides a device and a method for dividing outfield replaceable units L RUs, which relate to the field of product maintenance, and the device and the method introduce a grouped maintenance idea during L RU division, select an optimal unit combination by analyzing the influence of various maintenance correlations among components on possible L RU unit maintenance cost and maintenance time, and aiming at minimizing the total system maintenance cost and maximizing the maintenance saving time, and merge possible L RU units into a plurality of L RU groups with certain characteristics according to certain similarity criteria to generate a L RU multipart division scheme, thereby effectively improving the rationality of L RU planning design.

Description

Apparatus and method for dividing line replaceable unit (LRU)

technical field

The invention relates to the field of product maintenance, in particular to a method and device for dividing LRUs based on time and cost correlation

Background technique

Product design is the first and most important link in the entire life cycle of product design, manufacture, assembly, use and recycling. The design of LRU is mainly to improve the convenience of field replacement, mainly considering field fault detection and fault diagnosis. , Replacement, restoration of use of the test is simple. The design of a complex system is affected by various factors. On the basis of satisfying the functional design of the product, the planning of the field replaceable unit (LRU) must be synchronized with the functional design and iterate in coordination with each other. In particular, the division of LRU determines the advantages and disadvantages of maintainable design to a large extent. Therefore, reasonable LRU planning can greatly save maintenance time in field maintenance, reduce unplanned downtime caused by faults, and improve equipment system reliability. Product design tradeoffs and optimizations can be achieved to improve repair economy while reducing product repair difficulty throughout the life cycle.

The usual LRU planning is: first obtain a preliminary functional unit list according to the product's function definition file FDD; secondly, carry out an engineering classification of the main factors affecting the LRU planning and design, on the basis of the basic realization of product performance, combine the overall layout design and Validation and evaluation of maintainability-related designs. It can be seen that the traditional LRU planning process is only a qualitative analysis of the LRU. Since the effect of maintainability is mainly reflected in the time and cost saved by maintenance, the above qualitative planning process is not convenient to measure and reflect the actual maintainability of the product. .

In particular, most of the existing maintenance optimization models are only for a single component, that is, the physical structure, failure mode and even maintenance costs between components are considered to be independent of each other. That is to say, in the current complex system, the optimal maintenance interval of each component is determined according to the maintenance strategy of the single component, but in fact, for the complex system, due to the extensive Existing, making the internal components of the system interact and influence each other, that is, the maintenance intervals of each component are not the same, and some are even very different, so it is impossible to perform according to these maintenance intervals,

With the increasing emphasis on maintenance, the requirements for the accuracy and rationality of maintenance planning are also getting higher and higher. The establishment of a more accurate and reasonable maintenance optimization model can optimize the model of complex systems, improve the maintenance efficiency and effect, reduce costs, and be more and more widely used in system maintenance planning. The method of planning LRU only by qualitative analysis can no longer meet the requirements of the maintenance characteristics of the system.

SUMMARY OF THE INVENTION

In order to solve the problems existing in the prior art, the present invention provides a quantitative LRU planning device and method based on time saving and cost saving. The influence of maintenance correlation on the maintenance cost and maintenance time of possible LRU units, with the goal of minimizing the total maintenance cost of the system and maximizing the maintenance time saving, select the optimal unit combination, and classify the possible LRU units according to a certain similarity criterion Merge into several LRU groups with similar characteristics to generate LRU partition scheme of multi-component system, which effectively improves the rationality of LRU planning and design.

In order to achieve the technical purpose of the present invention, one aspect of the present invention provides a device for dividing a field replaceable unit LRU, including:

In the process of product design, the maintenance correlation analysis is carried out on the components that have been identified as the same group, and the analysis modules of multiple correlation sets are obtained;

Perform maintenance cost and maintenance time calculation on the correlation set obtained in the analysis module, and obtain a calculation module for the maintenance cost and maintenance time generated by each correlation set;

Comparing the maintenance cost and maintenance time generated by each correlation set obtained in the calculation module, and judging to obtain the judgment module of the maintenance set with less maintenance cost and shorter maintenance time;

According to the maintenance set obtained by the judgment module, the components in the non-maintenance set and the components not determined to be in the same group are regarded as the processing module of the minimum replaceable unit; and

The maintenance set obtained by the judging module and the minimum replaceable unit obtained by the processing module form the output module of the LRU division scheme of the field replaceable unit.

The components that have been determined to be in the same group are obtained by grouping the components according to the overall replaceability of manufacture or use by the grouping module.

In order to achieve the technical purpose of the present invention, a second aspect of the present invention provides a method for dividing the field replaceable unit LRU, including:

In the process of product design, use the analysis module to conduct maintenance correlation analysis on the components that have been identified as the same group, and obtain multiple correlation sets;

Use the calculation module to calculate the maintenance cost of the components in the correlation set, and obtain the maintenance cost generated by the maintenance of each correlation set; use the calculation module to calculate the maintenance time of the components in the correlation set, and obtain the maintenance cost of each correlation set. The set of dependencies yields the required repair time;

Use the judgment module to compare the maintenance cost and required maintenance time of each correlation set, and obtain the maintenance set with less maintenance cost and shorter maintenance time;

Using the processing module, the components that are not in the maintenance set and the components that are not determined to be in the same group are regarded as the minimum replaceable unit, and the LRU division scheme of the field replaceable unit is obtained through the output module.

Wherein, each correlation set includes at least two components of the same group.

Wherein, the maintenance correlation includes failure correlation, time correlation, structural correlation and functional correlation analysis.

Wherein, the correlation set includes a fault correlation set, a time correlation set, a structural correlation combination and a functional correlation set.

Wherein, the maintenance cost includes direct maintenance cost, failure loss cost and downtime loss cost.

Wherein, the calculation of maintenance costs for the components in the correlation set includes:

Under the influence of time factor, the maintenance cost incurred by the components in the maintenance correlation set;

Under the influence of functional factors, the maintenance cost incurred by the components in the maintenance correlation set;

Under the influence of structural factors, the maintenance costs incurred by the components in the maintenance correlation set;

Among the correlations of time, function and structure, the factors that affect the maintenance cost of the components in the correlation set with the greatest influence are selected to calculate the maintenance cost saved.

In particular, under the influence of the time factor, the maintenance cost generated by the components in the maintenance correlation set is obtained through the following steps:

Set dummy variables for each component requiring downtime for maintenance and for each component requiring no downtime for maintenance;

The maintenance cost of components is calculated according to the set dummy variables, the downtime loss caused by unit time during maintenance at a certain time, the maintenance time required by different components, and the fixed maintenance cost apportioned.

其中W表示虚拟变量。Among them, the dummy variable is

where W represents a dummy variable.

Wherein, the maintenance cost of the component is calculated according to the set dummy variable, the downtime loss caused by unit time during maintenance at a certain time, the maintenance time required by different components, and the apportioned fixed maintenance cost:

表示部件i和j分摊的固定维修费用，

表示时间因素影响下，维修相关性集合中的部件产生的维修费用。Among them, i represents a hypothetical component, j represents another hypothetical component, t represents a certain time, C _Stop (t) represents the downtime loss caused by unit time during maintenance at time t, and T _i (t) represents the maintenance required for component i time, T _j (t) represents the maintenance time required for component j,

represents the fixed maintenance cost shared by parts i and j,

Indicates the maintenance cost incurred by the components in the maintenance correlation set under the influence of time factor.

In particular, under the influence of functional factors, the maintenance cost generated by the components in the maintenance correlation set is determined by the dummy variables set above, the logistics delay time, the distance from the location where the equipment fails at a certain moment to the support point, The average transportation speed and the unit loss cost caused by late delay at a certain time are calculated and obtained.

Among them, the maintenance cost of the component is calculated by the dummy variables and the logistics delay time, the distance from the location where the equipment fails at a certain time to the support point, the average transportation speed, and the unit loss cost caused by the late delay at a certain time. The following formula calculate:

表示功能因素影响下，维修相关性集合中的部件产生的维修费用。Among them, i represents a hypothetical component, j represents another hypothetical component, t represents a certain time, C _Stop (t) represents the downtime loss caused by unit time during maintenance at time t, and T _i (t) represents the maintenance required for component i time, T _j (t) is the maintenance time required for component j, ΔT ² _ij (t) is the logistical delay time,

Indicates the maintenance cost incurred by the components in the maintenance dependency set under the influence of functional factors.

in,

Among them, S(t) is the distance from the faulty part of the equipment to the support point at time t, and V ₀ is the average transportation speed. C _stop (t) is the unit loss cost due to late delay at time t.

In particular, under the influence of structural factors, the maintenance cost of the components in the maintenance correlation set is

为部件i和部件j由于结构相关性而节省的维修停机时间，C_p单位人工费用，

表示结构因素影响下，维修相关性集合中的部件产生的维修费用。Among them, i represents a hypothetical component, j represents another hypothetical component, t represents a certain time, C _Stop (t) represents the downtime loss caused by unit time during maintenance at time t, and T _i (t) represents the maintenance required for component i time, T _j (t) represents the maintenance time required for component j,

is the maintenance downtime saved for part i and part j due to structural dependencies, C _p unit labor cost,

Represents the maintenance cost incurred by the components in the maintenance correlation set under the influence of structural factors.

Wherein, the calculation of the maintenance time for the components in the set includes:

The repair time required to repair the components in the collection under the influence of functional factors;

The repair time required to repair the components in the set under the influence of structural factors;

Among the functional and structural dependencies, the factors that have the greatest influence on the maintenance time of the components in the correlation set are selected to calculate the saved maintenance time.

In particular, under the influence of functional factors, the repair time required to repair the components in the set is obtained by the following steps:

The maintenance steps of the maintenance event and the corresponding standard maintenance time are counted, and the maintenance steps and the corresponding standard maintenance time of each maintenance time are obtained;

The traversal method is applied to calculate the maintenance time associated with the structure.

Wherein, the statistics of maintenance steps of maintenance events and their corresponding standard maintenance time may be represented by a two-dimensional array. For example, assuming that there are two types of maintenance events 1 and 2, when represented by a two-dimensional array, the first column represents Maintenance step number, the letters m _i and n _j in the second column represent the specific value of the corresponding maintenance time, as shown in formula (5):

表示维修事件1，

表示维修事件2，两个数组中第一列的工步编号，如发现

则

When applying the traversal method to calculate the maintenance time related to the structure, use

represents maintenance event 1,

Indicates maintenance event 2, the step number in the first column of the two arrays, if found

but

In summary:

where i represents one part of the hypothesis, j represents the other part of the hypothesis,

In particular, under the influence of structural factors, the maintenance time required for the maintenance of the components in the set is obtained from the distance from the faulty part of the equipment to the support point at a certain moment, and the average transportation speed.

Assuming that component i and component j are functionally related, the time saved is shown in Equation 7:

Among them, i represents one component, j represents another hypothetical component, S(t) is the distance from the faulty part of the equipment to the guarantee point at time t, and V ₀ is the average transportation speed.

Wherein, the components that have been determined to be in the same group are obtained through the following steps:

In order to achieve the technical purpose of the present invention, the third aspect of the present invention further provides a use of applying the method described in the first aspect to the maintenance of electromechanical products.

In order to achieve the technical purpose of the present invention, the fourth aspect of the present invention further provides a use of applying the device described in the second aspect to the maintenance of electromechanical products.

Beneficial effects:

1. The present invention considers the characteristics of interaction and mutual influence of the internal components of the existing complex system system when the LRU is divided, innovatively introduces the grouping idea, and improves the existing maintenance model to a certain extent. It is only for the actual situation of a single component ;

2. The present invention combines the possible LRU units into several LRU groups with similar characteristics according to a certain similarity criterion on the basis of considering the mutual influence relationship between the components, considering the maintenance characteristics between the various components of the system, as LRU division provides a new idea;

3. The present invention quantitatively analyzes the efficiency after the possible LRUs are combined into groups, and quantitatively calculates through the two indicators of maintenance time and maintenance cost;

4. The invention aims at minimizing the total maintenance cost of the sub-system and maximizing the time saving, and generates the LRU planning scheme of the multi-component system, which effectively improves the rationality of the LRU planning and design.

Description of drawings

FIG. 1 is a schematic structural diagram of an apparatus for dividing the field replaceable unit LRU according to Embodiment 1 of the present invention;

FIG. 2 is a flowchart of a method for dividing a field replaceable unit LRU provided by Embodiment 2 of the present invention;

Fig. 3 is the LRU scheme generation method framework of application embodiment 1;

Fig. 4 is the influence of the component correlation of the application example 1 on maintenance;

FIG. 5 is a classification of maintenance costs according to the application example 1. FIG.

Detailed ways

The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the preferred embodiments described below are only used to illustrate and explain the present invention, but not to limit the present invention.

Example 1

As shown in FIG. 1 , the device for dividing the field replaceable unit LRU provided by the present invention includes:

The analysis module 1 is used to perform maintenance correlation analysis on the components that have been determined to be in the same group to obtain multiple correlation sets;

The calculation module 2 is used to calculate the maintenance cost and maintenance time on the correlation set obtained in the analysis module, and obtain the maintenance cost and maintenance time generated by each correlation set;

Judging module 3, for comparing the maintenance cost and maintenance time generated by each correlation set obtained in the calculation module, and judging to obtain a judgment module for a maintenance set with less maintenance cost and shorter maintenance time;

The processing module 4 is used for, according to the maintenance set obtained by the judgment module, the components in the non-maintenance set and the components not determined to be in the same group as the minimum replaceable units;

The output module 5 is configured to form the LRU division scheme of the field replaceable unit from the maintenance set obtained by the judgment module and the minimum replaceable unit obtained by the processing module.

Further, the components determined to be in the same group are obtained by grouping the components according to the overall replaceability of manufacture or use.

For the parts not described in the above modules, refer to the content of Embodiment 2.

Example 2

As shown in FIG. 2 , the method for dividing LRUs by using the LRU dividing apparatus based on time and cost correlation provided in Embodiment 1 of the present invention includes the following steps:

Step S101, performing maintenance correlation analysis on the components that have been determined to be in the same group to obtain multiple correlation sets;

Specifically, the maintenance correlation includes failure correlation, time correlation, structural correlation and functional correlation analysis.

Wherein, the fault correlation includes type I fault correlation, type II fault correlation, impact damage correlation, and the like.

The fault correlation between components is divided into three categories: Type I fault correlation, that is, when a component fails, it will cause other components in the system to fail with a certain probability; Type II fault correlation, that is, when a component in the system fails, It will affect the failure rate of other components; impact damage is related, that is, in a two-component system, when one of the components fails, it will cause random damage to the other component. When the random damage accumulates to a certain extent, the component fails.

From the above definition of fault correlation, it can be seen that it only affects the system failure rate and has no direct impact on maintenance time and maintenance costs. Therefore, it is not considered in this paper.

Further, the type I fault correlation means that when a component fails, it will cause other components in the system to fail with a certain probability; type II fault correlation, that is, when one component in the system fails, it will affect the failure of other components. impact damage correlation, that is, in a two-component system, when one of the components fails, it will cause random damage to the other component. When the random damage accumulates to a certain extent, the component fails; the so-called structural correlation refers to the maintenance of a certain component. It is necessary to intervene in the maintenance process of another component, resulting in a partial overlap or intersection of the maintenance process of the two components.

Specifically, the correlation set includes a fault correlation set, a time correlation set, a structural correlation set, and a functional correlation set.

Step S102, performing maintenance cost calculation on the components in the correlation set to obtain the maintenance cost generated by the maintenance of each correlation set;

Specifically, the maintenance cost includes direct maintenance cost, failure loss cost and downtime loss cost.

Further, the direct maintenance costs include maintenance material costs, maintenance labor costs, etc.; failure loss costs include facility costs, equipment costs, management costs, and the like.

Specifically, the maintenance cost calculation for the components in the correlation set is calculated through the following aspects:

Under the influence of time factor, the maintenance cost incurred by the components in the maintenance correlation set;

Under the influence of functional factors, the maintenance cost incurred by the components in the maintenance correlation set;

Under the influence of structural factors, the maintenance costs incurred by the components in the maintenance correlation set;

Step S103, performing maintenance time calculation on the components in the correlation set to obtain the maintenance time required for the generation of each correlation set for maintenance;

The repair time required to repair the components in the collection under the influence of functional factors;

The repair time required to repair the components in the collection under the influence of structural factors.

Step S104, compare the maintenance cost and required maintenance time of each correlation set, and obtain a maintenance set with less maintenance cost and shorter maintenance time;

Step S105, taking the components not in the maintenance set and the components not determined to be in the same group as the minimum replaceable unit, to obtain the LRU division scheme of the field replaceable unit.

In practical application, the specific steps are as follows:

1. Preliminarily judge whether there is maintenance correlation between the units, and conduct correlation analysis on it

First, for the group idea introduced, four dependencies in group maintenance are considered, including fault correlation, time correlation, structural correlation and functional correlation, among which, functional correlation is divided into two categories. Then, the possible LRUs are judged one by one whether there is a correlation between the units, and if there is a maintenance correlation, it is judged as a unit that can be grouped, and a preliminary analysis of the correlation exists between the units that can be grouped.

2. Calculate the average maintenance cost saved by grouping correlated units

Combined with the relevant maintenance units obtained in step 1, analyze the maintenance costs that can be saved by grouping them. Among them, the maintenance cost saved can be analyzed and calculated from the following four aspects: time-related, functional-related, structural-related and the combined effect of the three.

分别取两个虚拟变量w_i和w_j如式(1)和(2)。(1) Assuming that component i and component j are time-dependent, the downtime loss caused by unit time during maintenance at time t is C _Stop (t), and the maintenance time required for components i and j are respectively T _i (t), T _j (t), the apportioned fixed maintenance cost is

Take two dummy variables w _i and w _j respectively as formulas (1) and (2).

Then the cost savings of component i and component j due to time correlation at time t is

(2) The maintenance cost saved due to functional dependencies is shown in equation (4).

S(t)为t时刻装备发生故障的部位到保障点的距离，V₀为平均运输速度。C_Stop(t)表示t时刻单位时间停机损失的费用。where ΔT ² _ij (t) is the logistical delay time, and

S(t) is the distance from the faulty part of the equipment to the support point at time t, and V ₀ is the average transportation speed. C _Stop (t) represents the cost of downtime per unit time at time t.

(3) The maintenance cost saved by component i and component j due to structural correlation at time t is expressed as formula (5)

为部件i和部件j由于结构相关性而节省的维修停机时间，C_p单位人工费用， T_i(t)和T_j(t)分别为部件i和j需要的维修停机时间。in

is the maintenance downtime saved for parts i and j due to structural dependencies, C _p unit labor cost, and T _i (t) and T _j (t) are the maintenance downtime required for parts i and j, respectively.

Assuming that the maintenance costs required before the groupable unit i and the groupable unit j are grouped are C _i , C _j , respectively, the number of times each groupable unit needs to be replaced in the entire life cycle is the failure rate λ _i , λ _j , the corresponding mean time between failures (MTBF) in the life cycle is _Vi , V _j , then the average maintenance cost in the whole life cycle can be expressed as:

η=C _i /V _i +C _j /V _j =C _i λ _i +C _j λ _j (27)

Assuming that the cost that can be saved after grouping unit i and unit j that can be grouped is ΔC, the number of replacements required for the unit that can be grouped in the entire life cycle after grouping is the failure rate λ, which corresponds to the lifetime The mean time between failures (MTBF) in the cycle is W, then the average maintenance cost in the whole life cycle can be expressed as:

μ=(C _i +C _j -ΔC)/W=(C _i +C _j -ΔC)·λ (28)

The average maintenance cost saved by grouping unit i and unit j that can be grouped is

ω=λ·ΔC (10)

3. Calculate the average maintenance time saved by grouping correlated units

Similar to step 2, combined with the maintenance units with correlation obtained in step 1, analyze the maintenance time saved after grouping them. The saved maintenance time can be calculated from three aspects: function correlation, structure correlation and the combined effect of the two. .

(1) Calculation of structure-related time

First, the maintenance steps of the two types of maintenance events and their corresponding standard maintenance time are obtained, and represented by a two-dimensional array, where the first column represents the maintenance step number, and the letters m _i and n _j in the second column represent the corresponding maintenance time. specific value:

和

两个数组中第一列的工步编号，如发现

则

Then, using the traversal method, traverse

and

The step number in the first column of the two arrays, if found

but

In summary:

(2) Function related time calculation

The time saved due to functional relevance II is shown in equation (13):

Among them, S(t) is the distance from the faulty part of the equipment to the support point at time t, and V ₀ is the average transportation speed.

Assuming that the maintenance time required before the groupable unit i and the groupable unit j are grouped are T _i , T _j , respectively, the number of times each groupable unit needs to be replaced in the entire life cycle, that is, the failure rates λ _i , λ _j , the corresponding mean time between failures (MTBF) in the life cycle is X _i , X _j , then the average maintenance time in the entire life cycle can be expressed as:

α=T _i /X _i +T _j /X _j =T _i ·λ _i +T _j ·λ _j (25)

Assuming that the time that can be saved after grouping unit i and unit j that can be grouped is D T, the number of replacements required for the unit that can be grouped in the entire life cycle after grouping is the failure rate λ, which corresponds to the lifetime The mean time between failures (MTBF) in the cycle is Y, then the mean time to repair in the entire life cycle can be expressed as:

β=(T _i +T _j -ΔT)/Y=(T _i +T _j -ΔT)λ (26)

That is: the average maintenance time saved by the system after grouping is γ=λ·ΔT

4. Determine which correlations to consider and determine grouping scenarios

Considering step 2 and step 3 comprehensively, make corresponding trade-offs based on time and cost for the units that can be grouped, comprehensively consider saving time and cost, and determine the most suitable correlation for the system. Determine what dependencies to consider and combine parts into groups. And weigh each grouping scheme to select the optimal grouping scheme. The trade-off method based on time and cost is shown below.

For different systems, the importance of maintenance cost and maintenance time is different, so the cost and time can be weighted according to the importance of maintenance time and maintenance cost in actual maintenance activities. Let the weight of maintenance time be a and the weight of maintenance cost be b.

(1) Judging the impact of correlation on the correlation set

Normalize maintenance time savings and maintenance costs. Let the flat maintenance time and maintenance cost of all components in the p-th correlation set without grouping be denoted as α _p and η _p , and the maintenance time and maintenance cost saved due to the k-th maintenance correlation are denoted as γ _pk and ω _pk (k=1, 2, 3), where k=1 is temporal correlation, k=2 is functional correlation, and k=3 is structural correlation.

Then the influence of the k-th maintenance correlation on the p-th correlation set is

The correlation corresponding to the maximum value in Effect _p1 , Effect _p2 , and Effect _p3 is selected as the correlation factor that has the greatest impact on the correlation set.

(2) Select the optimal grouping scheme

Assuming that there are l correlation sets, the maintenance time and maintenance cost saved by the p-th correlation set due to the correlation factor that has the greatest influence on it are denoted as γ _p and ω _p (p=1, . . . , l). The average maintenance time and average maintenance cost in the whole life cycle of all components in the system without group time are recorded as T _z and C _z

Then the impact of maintenance time and maintenance cost on the p-th correlation set is recorded as

Sort Effect _p (p=1,...,l) from large to small and summarize them into grouped solutions. The scheme should cover all groupable units and there should be no duplication of units. It is assumed that there are h grouping schemes, and the qth grouping scheme has N ₀ correlation sets. Then the influence of maintenance time and maintenance cost on the qth grouping scheme is:

where Effect _w represents the effect of the wth correlation set in the qth grouping scheme.

Compare Effect ^q (q=1,...,h), and select the grouping scheme corresponding to the maximum value as the optimal grouping scheme.

5. Summarize the units that cannot be grouped and the grouped units to form an LRU partition scheme

Summarize the units that cannot be grouped in step 1 and the optimal grouping scheme in step 4 to form an LRU partition scheme.

Application Example 1

Taking an electromechanical product as an example, its system has only 5 parts, and the part numbers are 1, 2, 3, 4, and 5; maintenance resources are sufficient; according to the system data, part 1 and part 2 are structurally related, and part 3 and part 4 has functional dependencies and time dependencies, and part 1 and part 4 have time dependencies.

Among them, the maintenance time required for component 1 is T ₁ (t) = 10 minutes, and the required maintenance cost is 2,000 yuan; the maintenance time required for component 2 is T ₂ (t) = 20 minutes, and the required maintenance cost is 1,500 yuan; , the maintenance time required for component 3 is T ₃ (t) = 10 minutes, and the required maintenance cost is 1,000 yuan; the maintenance time required for component 4 is T ₄ (t) = 15 minutes, and the required maintenance cost is 2,000 yuan; The downtime loss caused by unit time at time t is C _Stop (t) = 1 yuan, and the labor cost per unit time is C _p (t) = 0.01 yuan.

部件3和部件4由于功能相关性分摊的固定维修费用为

部件3和部件4由于时间相关性分摊的固定维修费用为

部件1和部件4由于时间相关性分摊的固定维修费用为

According to the system data, the fixed maintenance cost shared by component 1 and component 2 due to structural dependencies is

The fixed maintenance costs for parts 3 and 4 due to functional dependencies are

The fixed maintenance costs for parts 3 and 4 due to time dependencies are

The fixed maintenance costs for parts 1 and 4 due to time dependencies are

Maintenance downtime savings due to maintenance dependencies for all components is considered the same as 5 minutes. The failure rate of all components is regarded as the same as λ _i = 1% (i = 1, 2, 3, 4), the failure rate after component 1 and component 2 are grouped λ ₁₂ = 1.5% The failure rate after component 3 and component 4 is grouped rate λ ₃₄ = 2%, failure rate λ ₁₄ = 1.5% after component 1 and component 4 are grouped; the maintenance cost before all components are regarded as the same as C _i = 2000 yuan (i = 1, 2, 3, 4), the weight of maintenance time is a=0.5, and the weight of maintenance cost is b=0.5.

According to the above content, the LRU of the electromechanical product is divided. When dividing, refer to the LRU scheme generation method framework shown in Figure 3, the impact of component dependencies on maintenance shown in Figure 4, and the maintenance cost classification shown in Figure 5. ,Specific steps are as follows:

1. Judgment can be grouped into units

Since components 1, 2, 3, and 4 have maintenance dependencies with other components, but component 5 has no maintenance dependencies with other components, it is judged that components 1, 2, 3, and 4 can be grouped, and component 5 is not. group unit

2. Calculate the average maintenance cost saved by grouping correlated units

a) The first correlation set is Part 1 and Part 2, the average maintenance cost saved due to structural correlation is

b) The second correlation set is Part 3 and Part 4, the average maintenance cost saved due to functional correlation is

Its average maintenance cost saved due to time dependence is

ω ₂₁ =λ ₃₄ ·ΔC ¹ ₃₄ =2%·(80+1·10·60)=13.6 yuan

c) The third correlation set is Part 1 and Part 4, whose average maintenance cost saved due to time correlation is ω ₃₁ =λ ₁₄ ·ΔC ¹ ₁₄ =1.5%·(80+1·10·60)=10.2 yuan ;

3. Calculate the average maintenance time saved by grouping correlated units

a) The first correlation set is part 1 and part 2, whose average maintenance time saved due to structural correlation is

γ ₁₃ =λ ₁₂ ·ΔT ₁₂ =1.5%·min(T ₁ (t),T ₂ (t))=1.5%·10·60=9s;

b) The second correlation set is part 3 and part 4, whose mean maintenance time saved due to functional dependencies is γ ₂₂ =λ ₃₄ ·ΔT ₃₄ =2%·min(T ₃ (t),T ₄ (t) )=2%·10·60=12s;

4. Determine what dependencies to combine components to consider and determine grouping options

a) It can be seen from the assumption that only the second correlation set has two kinds of correlations at the same time. It is necessary to measure the impact of functional correlation and temporal correlation on the correlation set to determine which correlation to consider in the group:

Then the effect of functional correlation on the second correlation set is:

Then the effect of temporal correlation on the second correlation set is:

Obviously Effect ₂₂ > Effect ₂₁

The functional dependencies are then considered in the grouping of components 3 and 4 .

b) The effect of repair time and repair cost on the first correlation set:

The effect of repair time and repair cost on the second correlation set:

The effect of repair time and repair cost on the third relevant set:

Groupable grouping schemes for parts 1, 2, 3, 4 are:

Scheme 1 {(1,2),(3,4)}, its Effect ¹ =0.22+0.33=0.55;

Scheme 2 {(1,2),3,4}, its Effect ² =0.22;

Scheme three {1,2,(3,4)}, its Effect ³ =0.33;

Scheme 4 {(1,4),2,3}, its Effect ⁴ =0.08;

Scheme five {1, 2, 3, 4}, its Effect ⁵ =0.

5. Determination of LRU division scheme

Summarize the units that cannot be grouped in step 1 and the optimal grouping scheme in step 4, and finally determine the LRU partition scheme as {(1,2),(3,4),5}.

Although the present invention has been described in detail above, the present invention is not limited thereto, and various modifications can be made by those skilled in the art in accordance with the principles of the present invention. Therefore, all modifications made in accordance with the principles of the present invention should be understood as falling within the protection scope of the present invention.

Claims (10)

1. A device for dividing a field replaceable unit LRU, characterized in that, comprising: In the process of product design, the maintenance correlation analysis is carried out on the components that have been identified as the same group, and the analysis modules of multiple correlation sets are obtained; Perform maintenance cost and maintenance time calculation on the correlation set obtained in the analysis module, and obtain a calculation module for the maintenance cost and maintenance time generated by each correlation set; Comparing the maintenance cost and maintenance time generated by each correlation set obtained in the calculation module, and judging to obtain the judgment module of the maintenance set with less maintenance cost and shorter maintenance time; According to the maintenance set obtained by the judgment module, the components in the non-maintenance set and the components not determined to be in the same group are regarded as the processing module of the minimum replaceable unit; and The maintenance set obtained by the judging module and the minimum replaceable unit obtained by the processing module form an output module of the LRU division scheme of the field replaceable unit. 2 . The apparatus of claim 1 , wherein the components determined to be in the same group are obtained by grouping the components according to overall replaceability of manufacture or use. 3 . 3. A method of using the device of claim 1 for dividing a line replaceable unit (LRU), comprising: In the process of product design, use the analysis module to carry out maintenance correlation analysis on the components that have been identified as the same group, and obtain multiple correlation sets; Use the calculation module to calculate the maintenance cost of the components in the correlation set, and obtain the maintenance cost generated by the maintenance of each correlation set; use the calculation module to calculate the maintenance time of the components in the correlation set, and obtain the maintenance cost of each correlation set. The set of dependencies yields the required repair time; Use the judgment module to compare the maintenance cost and required maintenance time of each correlation set, and obtain the maintenance set with less maintenance cost and shorter maintenance time; Use the processing module to take the components that are not in the maintenance set and the components that are not determined as the same group as the smallest replaceable unit, and obtain the LRU division scheme of the field replaceable unit through the output module; Wherein, each correlation set includes at least two components of the same group. 4. The method of claim 3, wherein the maintenance correlation comprises failure correlation, time correlation, structural correlation and functional correlation analysis, and the correlation set comprises a fault correlation set, time correlation A set of correlations, a combination of structural correlations, and a set of functional correlations. 5. The method of claim 3, wherein the maintenance costs include direct maintenance costs, failure loss costs and downtime loss costs. 6. The method of claim 3, wherein the performing maintenance cost calculation on the components in the correlation set comprises: Under the influence of time factor, the maintenance cost incurred by the components in the maintenance correlation set; Under the influence of functional factors, the maintenance cost incurred by the components in the maintenance correlation set; Maintenance costs incurred by components in the maintenance-dependent set under the influence of structural factors; and Among the correlations of time, function and structure, the factors that affect the maintenance cost of the components in the correlation set with the greatest influence are selected to calculate the maintenance cost saved. 7. The method of claim 3, wherein the performing maintenance time calculation on the components in the set comprises: The repair time required to repair the components in the collection under the influence of functional factors; The repair time required to repair the components in the collection under the influence of structural factors. 8. The method of claim 3, wherein the components determined to be in the same group are obtained by grouping the components according to overall replaceability of manufacture or use. 9. A use of the device of any one of claims 1-2 for maintenance of electromechanical products. 10. A use of the method of any one of claims 3-8 for repairing electromechanical products.

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